Water-circulating heat extractor



FIG. 1 is a top view of a water-circulating heat extractor showing my new design, with the bottom view being identical;

FIG. 2 is a side view, with the opposite side view being a mirror image;

FIG. 3 is a right end view; and

FIG. 4 is a left end view. 

The ornamental design for a water-circulating heat extractor, substantially as shown and described. 